Machine tool, particularly of the hydraulic operated type



Ma 17, 19s.-

Original Filed June 29, 1932 5 Sheets-Sheet l INVENTORS I ATTORNEY .May 17, 1938. M55. CURTIS 2,118,025

MACHINE TOOL, PARTICULARLY OF THE HYDRAULIC OPERATE! TYPE Original Filed June 29, 1932 5 Sheets-Sheet 2 7b0L-$L 10E 510M FEED menu SOLENOI FIG. 3

F f 30 INVENTORfi ATTOREY 5 Sheets-Sheet 5 May 17, 1938. M. s. CURTIS MACHINE TOOL, PARTICULARLY OF THE HYDRAULIC OPERATED TYPE.

Original Filed June 29, 1932 M. s. CURTIS 2,118,025

Original Filed June 29 952 s shets -sheet 4,

INVENTQRQ BY MQ' L511: TORNEY May 17, 1938.

MACHINE TOOL, PARTICULARLY OF THE HYDRAULIC OPERATED TYPE May 17, 1938. M. s. CURTIS 2,118,025

MACHINE TOOL, PARTICULARLY OF THE HYDRAULIC OPERATED TYPE Original Filed June 29, 1932 5'Sheets-Sheet 5 Patented May 17,1938

MACHINE TUQL, PARTICULARLY @F THEE HYDRAULM) @PERATED Myron S. Curtis, Pawtuchet, it E, aaslgnor to William Wallace Potter, li'awtuchet, llst. K.

Application June 2%, i932; serial lilo. tidihdftfi Renewed April l'l, will? The invention relates to machine tools, where in there are coacting work-piece carrying members and tool carrying members.

In the production of the invention, l have adapted or embodied it in a station type multh ple spindle machine, such as forms the subject of my joint copending application No. 5:42AM and, because of special advantages in such a machine of that type, I illustrateand describe the invention with that type of machine, but this is by way of exemplificatlon or illustration of the invention and not limitation or restriction of the scope thereof.

One of the particular objects of the invention is the hydraulic'operation of the tool slides, so that'in a machine of the worlr-carrylng spindle type, there will be such control oi the pressure, especially for tool feed, that the ratio of tool feed to spindle revolution will be maintained at all times.

Other objects and advantages of the invention will be evident from the description which is given in the following specification.

The invention consists in whatever is defined by or is included within the terms or scope of the appended claims.

In the drawings:

Fig. 1 is a longitudinal section of a machine embodying the invention;

Figs. 2, 3 and i, are respectively, views of the hydraulic feed mechanism, with the operating 'valve'in three different positions;

Fig. 5 is a diagrammatic view of the electrical control and interlocks;

Fig. 6 is a diagrammatic view of an alternative hydraulic system;

Fig. '7 is a diagrammatic view of the electric connections and interlocks for operating the hydraulic system shown in Fig. 6.

The embodiment of the invention appearing in the drawings has the desirable characteristics in a machine in which the tool slide or slides. are hydraulically operated, the fluid under high and low pressure is furnished to the slide operating mechanism from an outside source, the high feeding pressure accurately metered in relation to the spindle rotation of the machine for the purpose of. feeding so that the feed is synchronous with the spindle revolutions; the hydraulic operations are under remote electric control; and

- feed control, and control of other functions of the machine are interlocked.

For the purpose of simplifying illustra 1 of drawings and description. of this specification, the parts of the machine illustrated the on the tube M and fastened to the carrier Ed by (til. Ze ith) companying drawings which are similar to or correspond with those of the aforesaid applicatlcn, will be given the same reference numerals which are used in that application.

Referring in Fig. l, base 5@ has bolted to it in 5 alignment spindle carrier housing iii gear housing and a rear housing Housing ti has revolvably located in it spindle carrier providedwith an end plate and carrying suitably supported in it a plurality of work carrying spin.- dles preferably spaced around the axis of the carrier lid. Spindle carrier 5% may be indexed V in a step by step manner by motor dd (see Fig. 5) which rotates shaft till carrying worm mil, (Fig. l) meshing a worm gear lid on an inden dish The dish tit carries a roll which successively engages in soul-spaced slots dd provided in the spindle carrier and plate Elli after, the manner of the well known Geneva movement. The spindle carrier when thus indexed, is 20 located and securely clamped by locking pins iii. Spindles 603 are driven by motor lit (see Fig. 5) connected with chain sprocket 925, and from the latter through a set of change gearing (gears lit, ideal id liii, pinion ltd and double gear Hit and ti, pinion lit, shaft ts, clutch til which drives gear ti on the spindle til) shown in Fig. 1; there being parts dd, fit, th for each spindle and each spindle -may be stopped and braked. while at the loading station, through internal cone tea clutch pinion ht and lined external cone 5%. The method of driving the spindles, clutching and declutchlng the same, operatlngthe work holding fixtures or' chucks the and indexing and clamping the spindle carrier 5d are all fully described in said copendlng application 542,156, and form no part of this invention.

Carrier it has axially bolted to it a tube us by means of a flanged collar 9t shrunk or welded bolts 9i. Slidable on the tube lid is tool carrier 93, which may he slid back and forth on tube til by thimble Mt fastened to rod M5 for the purpose of performing work, this motion being imparted from rod ltd to slide st -for the purpose of reciprocating the latter. Slide 93 carries necessary tools for operating upon worlcheld in fixer chucks and may have mounted thereil-tl are fully described in my plication as they form no part copendir'l;

;. do not iurtherdescribe the of this luv seine.

to Fit iii are cross slide bases 55 and low pressure with or from the machine.

branch pipe 23, leads from pipe I 9 to control valve well as main tool slide 93 receive'their motion from the primary operating rod I45.

, Fastened to one end of rod I45 is piston I2 slidable in cylinder I3. Referring to Figs. 2, 3 and 4,-it will be seen that an accumulator I4 or other suitable means furnishes fluidat a low pressure through pipe I5, cut-off valve I5, and

- pipe I1 to the return end of cylinder I3; and it also furnishes fluid under high pressure through pipe I5, stop valve I5, pipe I9, to metering pump 20 and thence through pipes 2| and 22 to the feed end of cylinder I3. The cut-ofi" valve I5 simultaneously connects or disconnects the high A 24, another branch pipe 25 leads from pipe 2| to control valve 24 and a pipe 25 leads from control valve 24 to the drain.

Control valve 24 contains a piston valve 21. which, when solenoid 28 is energized, is pulled into the position shown in Fig. 2, the solenoid circuit being hereafter explained. When in this position, high pressure fluid flows from the accumulator through pipe I8, stop valve I5, pipe I9, pipe 23, through valve 24, pipe 25, pipe 22 to the feed end of cylinder I3 in large volume. It also flows from pipe I9, to pipe 2I,"through metering pump or valve 29. Low pressure fluid is always supplied to the return end of the cylinder I3 from accumulator I4, but the low pressure resistance on the return side is overcome by the high pressure-on the feed side and, therefore, piston- I2, and consequently the slide reciprocating rod I45, is advanced rapidly in the direction of the arrow in Fig. 2, thereby advancing rapidly main slide 93 and cross slides 2I9 to their cutting positions. When this position is reached, solenoid 29 is energized in a way hereinafter to be described, and by plunger 35 operating lever 3|, which engages on a collar on the valve rod, moves valve 21 to the position shown in Fig. 3. When the valve 21 is in this position, high pressure fiuid cannot flow directly from pipe 23 to pipe 25, but must go through metering pump 20, (which pump is of a well known multipiston variable stroke type and is furnished with a gear 32 driven from gear I34, see Fig. 1, and consequently metering pump 20 rotates in synchronism with the spindles 55, because pump and spindles are geared together). now supplied in a small metered amount to'the feed side of piston I2 (overcoming the resistance of the low pressure on the return side of the piston) and consequently the various tool slides are given their feed motion on the; work at a measured rate synchronously, or in time with the spindle revolutions. Therate of feed is alterable by varying the stroke of the metering pump When the slide reaches the limit of its feed stroke, toolslide 93, is brought to a positive stop by stop rod I42, as in said copending application, and piston I2 discontinues its work operation feed, movement. Pressure immediately begins to rise in pipe 22, untilit reachesa-degree to overcome the resistance of spring 33, in a. cylinder 3 end of the feed stroke.

High pressure is the resistance of spring 33 causes piston 35 to move and thus close a control circuit by a switch 35 connected with said piston 35. The strength of the spring 33 may be varied by an adjusting nut 31. The time for piston 35 to move enough to close the circuit gives a desirable delay at the The circuit closed by switch 35 excites solenoid 35, as hereinafter described, which latter pulls valve 21 to the position shown in Fig. 4. The feed side of cylinder I3 is now connected directly with drain pipe 25 through pipes 22 and 25, and all pressure on the feed side of piston I2 is removed. As low pressure is maintained on the return side of the piston I2, it, together with the attached slides, being returned rapidly to the starting point.

The operation of the solenoids, for controlling the hydraulic feed, together with their interlocks, by the outer elements of the machine is diagrammatically shown in Fig. 5. In this diagram. as in the aforesaid application, the terminals are designated by letters, and terminals with like letters are always connected. It will be noted that terminal A is always connected withone wire of the main line and the terminal D is always connected with a ground wire of the main line so that, when A and -D are connected, a current flows through the circuit.

Contactor 215 on panel 219 operates spindle motor I22 and contactor 239 oper'ates high speed drill motor 25I, through push buttons 29| and 255; and a cutout switch 299 is furnished for contactor 259 in the same manner as in said copending application, and therefore requires no further explanation.

The contactor 294 controls index motor 99- the functions of this motor being to revolve index disc' 95 which controls the indexing and locking of the spindle carrier 54, as in said copending application, and the movements of this index disc 95 must be interlocked with movements of the slide 93. For this purpose I provide on index disc 95 a dog 301 which operates plunger 3| 9, thereby operating switches 325, 325 and 321 so that, when disc 95 has completed all the functions incidental to indexing the spindle carrier 54, the

dog 351 pushes plunger 3I9 in, switch 321 first closescircuit between A and R; switch 325 then closes circuit between F and D; switch 325 then breaks the circuit between A and S, and when dog 351 moves away from plunger 3|9, it permits the reverse operation to take place,--namely:' switch 3'25 first closes circuit between A and S; switch dogs 435 and 431 which by acting on arm 438' close, respectively, normally open switches 439 and 445, thus completing. the circuits between A and E, and A and K, respectively. I also pro-. 'vide on panel 219 relays I, 442, 443 and 444,

the functions of which will be hereinafter described, and on push button panel- 259 is a reset switch 445, a. hand index switch 445, a fast ahead hand switch 441, a slow ahead hand switch 448, and a reverse hand switch 449.

The machine illustrated may be operated or controlled by hand or automatically. The hand operation, which I will first describe, is accomplished by hand push buttons 446, 441, 448 and 449. It must be made impossible to index the spindle carrier except when the tool slide 93 is in its extreme rear posltlon and it must be impossible to operate tool slide 93, except when the index is stopped in such a position that dog 30'! has pushed in plunger 3l9 and this must be so both inhand operation, and in automatic operation. To operate the index by hand, push button 446 is depressed. This first breaks the con nection between A and the slide operation push buttons, thus preventing their operation; it next connects A and S and, if slide 93 is in its extreme rear position so that dog 433 closesswitch 434, current will flow from S to I in contactor 435; thence to connection I in contactor 294, through thermally operated safety switch 3 I and solenoid 3l4 to connection D, thus forming a circuit through solenoid 3l4, energizing the same and closing motor switch 3I6, and starting motor 99 which operates disc 96. Motor 99 runs as long as button 4461is depressed and'stops as it is released.

Depressing fast ahead push button 44! connects A and E. and if index push button 446 is not depressed, but is 'in'the position illustrated. current flows from A to E, thence to E in relay 44!, through solenoid 450 to D, thus completing a circuit through the solenoid and. closing sw tches 45I and 452. Closing of the switch 452 allows current'to flow from A in contactor 294 to T if switch 316 is open in the position shown so that motor 99 is stopped; thence to T in relay 44L through switch 452 to H. thence to H in the.

'solenoid 28, causes the valve ,rod to operate switch'454 breaking the circuit between A and G.

The slow speed is operated by depressing button 448. Th s first breaks the connection between A and A thus cutting off current from the reverse switch 449. then completes the connection between A and K if switch 449 is in its inoperative position as shown, causing current to flow to K in relay 443 thence through coil 455 to connection D. This energizes coil 455 and closes sw tches 456 and 451. Closin of the switch 456 al ows a holding circu t to flow from A to P in. hydraulic panel 453. thence to P in relay 443, through. switch 456 to K, and thence through coil 455. Switch 451 comple es a circuit from A to Q in relay 443. thence to Q n hydraulic panel 453. thr ugh soleno d 29 to F. and if as before switch 326 in contactor 306 is closed. through to D. This completes the circuit through solenoid 29, thus ener izing the same and hv means or rod 30. lever 3| act ng on collar 21".,

moves valve21 to slow feed posit on shown in- Fig. 3. Movement of rod so. also causes switch 458 to break a holding circuit between A and 1?, thus de-energizing solenoid 455 and allowing sw tches 456 and 451 to open.

Depressing push button 449 closesthe circuit between A and L in panel 280, if switch 446 s in its inoperat ije position as shown, causing cur rent to flow to L in relay 444, thence through solenoid 459 to D, thusenergizing solenoid 459. This causes switches 460 and 46I to close. The

closing of switch 460 completes a holding circuit through solenoid 459 when switch 462 in panel 453, through solenoid coil 38 to F and thence from F to D in panel 306 if switch 326 is closed. This completes a circuit through solenoid 38 energizing the same and pulling valve 21 to reverse position shown in Fig. 4. Valve 21 when moved to the reverse position opens switch 462 thus breaking the hold ng circuit through coil 459 in' relay. 444 and allowing switches 460 and 46l to open. It is thus seen that by the action of switches 454, 458 and 462 in hydraulic panel 453, that the circuit through the operating solenoids is broken as soon as they have completed their work.

Automatic operation-Assume the tool slide is in its extreme rear position and a cycle of the machine has been-completed, but that spindle drive is operating and the clutch or clutches 60 are disconnected. The operator chucks a piece of work, then he starts the indexing of the spindle carrier 54. At the completion of the indexing, the tool slide 93 starts forward on the of work, as above stated, and after he has finished, he pushes the reset safety button 445, which causes the cycle to be repeated as soon as the slide reaches its extreme rear position. If he does not, however, press the reset push button 445, the machine stops until he does press this button.

The above generally described automatic cycle is accomplished thus: With the slide 93 at its extreme rear position, dog 433 will hold switch 434.

closed. The indexing has stopped in such position that dog 301 on index disc 96 has pushed plunger 3l9 into the position shown (Fig. 5). The operator chucks a piece of work and then Dresses reset button 445 which makes a connection between A and J permitting current flow to J in relay 442 and through coil 463 to D, thus energizing this coil and closing switches 464 and 465. Closing switch 464 connects J and R and, as R is connected with A through 32] on' panel 306, a holding circuit is formed through coil 463 so, when the operator releases button 445, coil 463 still remains energized. .Closing switch 465 connects A with S and, as S is connected with I on panel 435 current flows to I of contactor 294 energizing coil 3 and closing switch M6. The closing of switch 3l6 opens the circuit between A and T by switch 466 and closes the circuit between A and D by switch 451. This energizes coil 450 in relay 4 and closes switches 45! and 452. As G is connected with A on hydraulic panel 453, closing of switch 45! permits a holding circuit to go through coil 450' maintaining switch 452 closed, which connects T with H, but as this circuit .is broken by switch 466 on panel 294, no action takes place.

Closing switch 3l6 also starts motor 99 revolving to index d sc 96 which moves dog 30! away from plunger 3l9. I This allows the plunger 3 I 9 to automatically move (to the right of Fig. 5) first, to close switch 325 connecting A with fore, index disc 96.

S, thereby maintaining a holding circuibthrough the index solenoid 3 I 4 by connections I; secondly, to open switch 326 breaking the circuit between F and D, thereby making it impossible to energize any of the hydraulic feed solenoids while the index is taking place; and, thirdly, to open the circuit between A and R by switch 321, which breaks the holding circuit through solenoid 463 of relay 442, allowing switches 464 and 465 to open. The opening of switch 464 breaks the holding circuit through solenoid 463 and the opening of switch 465 breaks a circuit between A and S, but, as A is still connected to S on panel 306, no change takes place;

As the index disc finishes its cycle or revolution, dog 301 again engages on plunger 3| 9 to move it to the position shown in Fig. by, first, closing switch 321, but no action takes place as this circuit is broken by switch 464 of relay 442. The plunger 3 l9 then closes switch 326 connecting F and D, making it possible to energize the hydraulic solenoids, and then breaks a circuit between A and S by switch 325, which breaks the holding circuit through I of contactor 294, thus de-energizing coil 3l4and allowing switch M6 to open, stopping inde king motor 99, and, there- This operation of the switch 3I6 also breaks the connection between A and E of contactor 294 by opening switch 461, but as a holding circuit current is flowing through E from G, the solenoid 458 remains energized;.and also connects A to T by closing switch 466. This causes current to flow from A to T of contactor 294, from Tv to.H of relay 441, thence to H on hydraulic panel 453 .through solenoid 28 to F, thence from F to D on panel 306, which energizes solenoid 28 causing it to pull hydraulic valve 21 into the fast ahead position shown in Fig. 2. This movement of the valve 21 opens switch 454 on the hydraulic panel 453, thus breaking the connection between A and G and breaking the holding circuit through solenoid 456 of relay 4 allowing switches 45! and 452 to open, and deenergizing solenoid 28. The slide 93 now feeds fast ahead until dog 431 coacts with arm 438 on panel 435, which closes switch 440 connecting A with K and energizing coil 455 in relay 443. This energization of coil 455 closes switches 456 and 451 and, as A is connected with P on panel 453 by switch 458, a holding circuit is formed by the closing ofswitch 456 and the closing switch 451 completes the circuit between A and Q of relay 443, thence to Q in hydraulic panel 453,

through solenoid 29 to F, thence to F on panel 306 and through switch 326 to D, thus energizing solenoid 29, which moves rod- 38 so that it shifts valve 21, by means of lever 3| acting on collar 21a to slow feed position shown in Fig. 3. This movement of rod 30, also opens switch 458 on the hydraulic panel 453, breaking the holding circuit between A and P, allowing switches 456 and 451 of relay 443 to open, andde-energizing solenoid29. Slide 93 now feeds slowly until it reaches the end of its working stroke when, as before mentioned, pressure begins to build up in cylinder 34, until it causes piston 35 to move switch 36 to closev the circuit between A and L in hydraulic panel 453, which completes a circuit through coil 4590f relay 444, closingswitches 468 and 46L As A is connected with M by switch 462 on panel 453. when the slide is in the fast ahead or slow feed positions, a holding circuit is formed by switch 460 through coil 459. The closing of switch 461 of relay 444 completes a circuit between A and N of relay 444, thence to N in panel 453, through solenoid 38 to F. thence to D through switch 326 in panel 306. This energizes solenoid 38, causing it to pull valve 21 into reverse position as shown in Fig. 4, thislatter movement opening switch 462, breaking the holding circuit through coil 459 so that switches 460 and 46l open, and de-energizing coil 38. Consequently, the high pressure in the cylinder 43 and in pipe 22 is open to drain 26, and the low pressure from the accumulator or other source flows through. pipes l5 and I1 to the cylinder l3 thus rapidly returning the piston l2 and therefore the slide 93 to its rear position.

While these operations have been taking place, the operator has chucked a work piece in that spindle which is at the loading station and, upon completion of chucking, presses the hand reset push button 445, which connects A with J, thus energizing coil 463 of relay 442, closing switches 464 and 465. The closing of switch 464 completes a holding circuit through coil 463, by connections A and R on panel 386. connects A with S of relay 442 but, as this circuit is broken by switch 434 on panel 435, no action takes place. When, however, slide 93 reaches its extreme rear position, switch 434 is closed by dog 433, completing the circuit from S to I, thence to coil 3| 4 on contactor 294, thus starting the index disk 96 and then the cycle is repeated.

Should the operator, however, fail to press reset button 445, the coil 463 of relay 442 is not energized. Switches 464 and 465 remain open so that, when dog 433 closes switch 434 as the slide reaches its extreme rear position, no indexing takes place as the circuit is broken by switch 465 of relay 442. As soon as the operator energizes coil 463 by pressing hand reset push button 445, index takes place and the cycle repeats.

It may be desirable to feed the slide 93 "fast ahead" after dog 431 has thrown the feed into slow ahead. This is accomplished by dog 436, which moves arm 438 to close switch 439, making a connection between A and E, energizing coil 450 of relay 4 which closes switch 452, thus energizing fast ahead solenoid 28.

In Fig. 6, there is shown another hydraulic feeding system operated electrically, as shown diagrammatically in Fig. '7. In this case, there is utilized as a source of hydraulic power a variable displacement pump unit 466, similar, for instance, to that manufactured by the Oilgear Company, the construction of which is well known to the art, and driven by a motor not shown. It has a valve 461 with a valve rod 468, which can be operated by a hand lever 469 or hydraulically. When handle 469is in the position 469a, the hydraulic feed is on fast ahead, with the handle in the position 4691) it is on slow ahead, with the handle in the position 4690, it is in feed reverse, and when in the position 469, it is in neutral. Besides hand and hydraulic operation of this valve 461, there is provided electrical operation. The pump unit 466 has a variable stroke, highpressure pump for feeding and a constant volume low-pressure pump for quick motions and maintaining back pressure and, when valve rod 468 is in the fast ahead position, the constant volume low pressure is forced through'pipe 413 to the right hand or ahead side of cylinder l3a, and the left hand side of cylinder l3a is connected by pipe 414 with the exhaust. This causes piston H to be moved rapidly in the direction of the arrow and its piston rod I45 moves main tool slide 93 rapidly in its ahead direction. When the tools reach the work, solenoid 29a (Figs. 6 and 7) ener- The closing of switch 465 anaoes sized and the solenoid core 415, through" lever 414 pivoted on stud 411,- will engage collar 418 on rod 419 throwing valve rod 468 to place the valve 461 in feed work-operation position. In

this position, the right hand side of cylinder its is connected withthe variable feed high-pressure pump through pipe 413, and the left hand side of the cylinder is connected with the constant low-pressure through pipe 414, the sliderence in pressure causing piston I211, and hence tool slide 93, to move slowly for work-operation. When slide 93 reaches the end of its feeding work-operation stroke, it is brought to a dead stop by stop rod 4 42 (Fig. l) and pressure builds up in pipe 413 and consequently in valve Mid, through branch pipe 413i, until it is suflicient to overcome the resistance of spring 482 which holds ball valve 483 in its seat, spring 4&2 being calibrated to withstand any pressures necessary during work operation of the cutting tools. Liquid is then forced through pipe 4% to the left hand side of piston valve 485, in pilot valve ltt. It will be observed that the right hand end of piston valve 485 is connected by pipe 4M, and valve tilt to the low pressure pipe 414 by the check ball valve tilt in valve 488 and will lift from its seat under the pressure acting on piston valve tilt thus allowing valve 485 .to be shifted to the right. This connects pipe 4% (which is always connected with the low pressure constant volume pump) with pipe 4! and causes low pressure to flow into chamber 492 of valve chest tilt! and acts on piston 493 on valve rod 468 to force it to the right, thus moving the valve 4M and the handle ton to neutral or tool slide reversing positions as will now be described.

Chamber 494 of valve chest tilt, in which piston 495 is disposed, is connected by means of pipe 496 with drain pipe tor through pilotvalve 485, so that piston Milt can move to 'its extreme right hand position. Piston filth has a rod lth extending from it which abuts against piston 6% (but is not fastened to it) so that piston is moved by piston 493 in its movement towards the right, but is left by piston when the latter moves to its extreme left position.

Movement of piston use to its extreme right position throws valve rod lltti to place its valve it? inthe reverse position, and in this position the left hand end of cylinder its is connected by pipe 414 with the low pressure constant volume pump and the right hand end of cylinder tile is connected by pipe 4173 with the drain through pipes 441L684, pivot valve tit and pipe -ltill. This causes piston 82a to rapidly move until it reaches its extreme right hand position. Pressure then starts to build up in pipe W4 until it is able to lift ball not against the pressure of spring 3539? in valve M8, this spring being or" sui'hcient tension to re sist the pressure necessary to. return the tool slide to its extreme rear position. pressure is sumcient to lift valve 5%, the fluid flows through pipe dd? to the right hand side oi.

valve 485 in pilot valve body Gilli and as the left hand end of this valve is now connected with the drain through pipe tilt, valve ltlfii, pipe ifii, and pipe 413, valve 4% is shifted to its extreme left position. Chamber in is now connected by pilot valve 486 with the drain through pipes tilt and 491, and low pressure is applied to chamber from pipe 49d through pilot valve lilti and pipe 486, causing piston the to move to its extreme left hand position. As piston ist has only half the stroke of piston 493, it forces the latter and thereiore valve rod toll into neutral position When the where all pipes are filled with the same low pressure, and piston l2a remains stationary.

The cycle can now be restarted by throwing valve 468 into the fast ahead position either by hand, or automatically by energizing solenoid 28a.

Now it will be described the automatic .operation in connection with Fig. 7. It will be noted that the terminal connections are lettered and, as in the other case, connections that have similar letters are always electrically connected and, as in the other embodiment of our invention, panel 2W has the contactor 2% which operates spindle motor it? and a contactor 289 which operates high speed drill motor 26!. These motors are operated by start and stop buttons 283i and list in panel 2th and contactor its may be connected or disconnected from these push buttons through switch 2%. As the operation of these contactors does not formally part of-this invention, no description thereof is necessary This circuit is, like the preceding one, capable oi hand or automatic control.

fllo index the spindle carrier lit by hand. a push button t lt (on push-button panel 2%) depressed and first disconnects A and A thus preventing hand operation of the tool slide while indexing is taking place; push button 41% then connects A and S completing a circuit to S on slide panel lth and through switch llil to I, if tool slide 593 is in its extreme rear position, so that dog are closes switch ti l; thence to I on contactor 6th, through thermalsafety switch sit on contactor tilt and solenoid coil iil lto D. This energizes coil tit, which operates switch tit starting motor as, which continues to run as long as button Ml? is depressed and stops upon the release of said button. as soon as index motor to starts to revolve, index disc at moves away from button t ll is depressed, which first brcalrs the,

connection from n to it thus preventing the slow speed switch from being operated and, then connected it? with E, ii the tool-slide slow teed push button is in its upward or release position. This completes'a circuit from A to E, thence to it on relay i il, through coil not to D, thus energizing coil 41bit which closes switches dbl and dill. Closing switch dbl completes a holding circuit through coil new if G is connected with a on the hydraulic panel and the closing of switch connects T with H and as T is connected with A in contactor 2%, current allows to H on the hydraulic panel thence through solenoid the to F, thence to F on panel use, through switch 3% to D. This energizes coil 2% causing it to move valve plunger 3nd, by means oi rod ill; and lever tltiti, to position littl for starting the fast ahead .tooi-siide iced. Rod ilt, also at the end of its movement last mentioned, operates switch tilt breaking the circuit between A and G thus tie-energizing coil allowing switches not and not to open, the opening oi the latter de-energlaing coil Eda.

The slow tool-slide iced is operated by push button lilfl which, when depressed, first breaks the circuit between il and A thus preventing the operation of the high speed push button Mill; and then connects with K, it push button G ll is in its inoperative released or upward position. This completes a circuit between A and E; and

455 thereof to D, thus completing the circuit through coil 455, if switch 456 on panel 453 is connecting A with P, and the closing of switch 451 completes a circuit from A to Q, thence to Q on the hydraulic panel 453, through coil 29a thereon to F, thence to F on index panel 306 and through switch 326 to D. This completes a circuit through coil 29a-energizing the same and causing it-by means of rod 415, lever 416 and collar 418--to operate rod 419 a sumclent distance so that it pulls handle 469 into the slow ahead position. The operation of rod 415 also causes switch 458 to open, breaking the holding circuit through coil 455 allowing switches 456 and 451 to open, the opening of the latter deenergizing solenoid 29a.

When reverse by hand is desired, it is accomplished by means of hand lever 469.

The automatic cycle is similar to"that hereinbefore described and is accomplished thus: Assuming that the slide 93 to be at its extreme rear position with dog 433 holding switch 434 closed and'the index disk 96 to be stopped in such a position that dog 301 holds plunger M9 in the position shown, the operator chucks a piece of work in the spindle at the loading station and then depresses reset button 445. This connects A with J completing a circuit to J in relay 442 and through coil 463 thereof to D, thus energizing this coll which closing switches 464 and 465. Closing switch 464 connects R and J forming a holding circuit through coil 463 as R is connected with A on index panel 306. Switch 465 connects A with S causing a current to flow to S on tool-slide panel 435, thence to I, back to I on contactor panel 294, through coil 3 to D, thus energizing coil 3 and throwing switch 3l6. This starts index motor 99, breaks the circuit between A and T and closes the circuit between A and E on contactor panel 294, which latter completes a circuit through coil 450, energizing the same and closing switches 45l and 452. G105- ing switch 451 completes a holding circuit through coil 450 as A is connected with G on the hydraulic panel 453. Closing switch 452' connects H with T but, as this circuit is broken on contactor panel 294, no action takes place. As soon as the indexing starts, dog 301 moves away from plunger 3l9 allowing it to move with its bias to, first, closeswitch 325 establishing a circuit between A and S to complete a running circuit through coil 3; then causes switch 326 to break the circuit between F and D, preventing any operation of the tool-slide feed, while indexing is taking place; and then causes switch 321 to open between A and R, which breaks the holding circuit through coil 463 thus allowing switches 464 and 465 to open,- the latter breaking the starting circuit through coil 3l4.

As the indexing finishes, dog 301 again pushes in plunger 3l9 against its bias, first, connecting A with R by switch 321, but as this circuit is broken in relay 442, no action takes place: then connects D with F by switch 326, permitting operation of the feed solenoids 28a; and then breaks the circuit between A and S by'opening switch 325, which latter breaks the'cir'cuit through coil 3, de-energizi'ng the same and allowing switch 3l6 to open, stopping the index motor '99. The

opening of switch 3i6 also causes switch- 461 to break the starting circuit through coil453 and then closes switch 466 connecting A and T, forming a circuit from A through switch 452 to H on the hydraulic panel 453. Current now flows current passes to K on relay 443, through coil .irom H through coil 29a to F, thence from F to D in panel 306, thus energizing coil 29a and, as previously explained, starting the fast ahead feed and also opening switch454, breaking the holding circuit through coil 450 in relay 4, allowing switches 45l and 452 to open, the latter de-energizing coil 26a. Slide 93 is now in the fast feed ahead speed and continues so until dog 431 acts on arm 438 causing switch 440 to close the circuit between A andK on panel 435 which completes a circuit to K in relay 443 and thence through coil 455 to D, energizing the coil and closing switches 456 and 451. Closing switch 456 completes a holding circuit through the coil as A is connected with P in panel 453 and the closing of switch 451 completes a circuit from A to Q in panel 453, thence through coil 29a to F and from F to D in panel 306, thus energizing coil 29a and by rod 415 throwing valve rod 468 to feed ahead position. Movement of rod 415 opens switch 456, breaking the holding circuit through coil 455, allowing switches 456 and 451 to open, the latter de-energizing coil 420. The tool slide then feeds ahead until it reaches the end of its stroke when the reverse is operated by the pressure in valve 46! as hereinbefore explained. The slide then returns to its extreme rear position where it is thrown into/neutral by pressure in valve 468 as before explained.

While the above described cycle has been taking place, the operator chucks another piece and if after'chucking the piece he depresses button 445, relay 442 is operated to complete a circuit between A and S so that when slide 93 reaches its extreme rear position and dog 433 closes switch 434 a circuit is completed to I, thus operating switch 3l6 in panel 294. This starts the index and the cycle is repeated. If the operator does not press the hand re-set button 445, thus energizing relay 442, connection is not made between A and S in relay 442 and the closing of switch 434 will not start the index motor 99. The machine, therefore, remains stopped until the operator presses re-set button 445.

What is claimed is:

1. In a machine tool having a rotatable work spindle and means for rotating said spindle, the combination of a to and fro moving tool carrier, hydraulic means for moving the carrier to and fro relative to work on the spindle, and automatic means and including elements operated by the movement of said carrier when in predetermined positions for controlling the action of the hydraulic means, said hydraulic means including a cylinder with piston fluid pressure connections =communicating said hydraulic means on both automatic control means being electrical and ineluding a circuit having operating connections with a movable element of the hydraulic means and with a power-moved machine element that controls such circuit.

3. In a machine tool of the rotatable workalmost lid bination ofa single to and fro movable 'tool feeding means for the tools of each spindle, hydraulic means for moving the feeding means to and fro relative to work on the spindles, means for indexing the spindles from station to station and automatic means for controlling the action of the hydraulic means and said indexing means, said automatic meansincludlng electrical circuits having interlocking elements therein that prevent concurrent action of said diflerent members of the machine.

4. In a machine tool oi the rotatable worksupporting multi-spindle station type, the combination of a to and fro moving tool carrier, a single hydraulic means for moving the carrier to and fro relative to work on the spindles, means for indexing the spindles from station to station,

and automatic means for controlling the action oi the hydraulio'means and the indexing means, said automatic means including electrically actuated interlocking elements and actuated at pre determined positions of the tool carrier and said indexing means to prevent concurrent action of said carrier and said indexing means.

5. In a machine tool having a vvorlz holding spindle, the combination of a to and fro moving tool carrier, hydraulic means including a pressure recelving piston for moving the carrier to and fro relative to work on the spindle, and auto= 'matlc means for controlling the action of the hydraulic means, said hydraulic means including a single source of high and low pressure supply,

and. high and low pressure circuit connections from the pressure supply source to opposite sides of said pressure-receiving means, a meteiing pump in said high pressure connection and valve means in one of said connections and controlled hy the movement oi said carrier for rendering the functional operations oi said metering pump ei- :fective or ineffective.

d. in a machine tool having a coils-holding rotatable spindle, the combination of a to and fro moving tool carrier, hydraulic means for moving the carrier to and fro relative to wort: on the spindle, automatic means for controlling the action of the hydraulic means including high and low pressure supply means and means for controlling the high pressure supply in a fitted relation to spindle speed and includes a metering pump operatively controlled by the spindle and further including high and low pressure circuit connections from the pressure supply means to said pressure receiving means, and valve means controlling said pressure circuit connections.

"i. A machine tool comprising a rotatable wort: spindle, is to and fro moving; tool carrier, hydraulic means for moving the carrier to and ire relative to Work on the spindle including a cylinder and piston, said hydraulic means including high and low pressure supply means, and means that control high pressure supply in listed rela tion to spindle speed, whereby. ratio of spindle revolution and tool feed is maintained, such last-mentioned means including a metering pump operatively controlled by the spindle.

8. ll machine tool comprising a worlt rotatable spindle, a to and .iro carrier, hy draullc means for moving" the to and fro relative to work on spindle including cylinder and piston extending direction of movement of the tool senior, said operate the working movement of the tool carrier.

iii. A machine tool as in claim 5 in which the metering pump is driven synchronously with the spindle.

11. A machine tool as in claim 1 in which the hydraulic connections include a high and low pressure source of supply adapted to supply low and high pressure, respectively, at opposite sides of the piston, and the metering pump being in the high pressure connection between the pressure supply source and the piston, and valve means in the hydraulic means and controlled by said automatic means for selectively rendering the operation of said pressures effective or ineffestive.

12. In a machine tool having a work spindle or spindles and a to and fro moving too] carrier or carriers, means for rotating the spindle or spindies, hydraulic means for moving the carrier or carriers to and fro relative to work on the spindle, said hydraulic means including a metering pump driven synchronously with the spindles, and electrically actuated automatic means for controlling the action of the functional operation of the metering pump and of the hydraulic means to eiifect said to and fro movement of said carrier or carriers in timed relation with the movement of said carrier or carriers, said automatic means including electrically actuated interlocking elemeats that prevent concurrent action oi said differvent functional operations of said hydraulic means,

porting spindle and a tool carrier reciprooahle to and from the work on the spindle, a driving means for rotating said spindle, hydraulic means for feeding the carrier toward the worlr. on the spindle, including a iluid supply having a metering device therein, means actuating the meterlog device synchronously with the spindle, Whereby the movement of the carrier may he maintained in constant ratio with the rotation of the spindle, a valve connected with said fluid supply in one of its positions icy-passing said metering device and in another of its positions releasing said pressure, means for moving the carrier away from the spindles when valve is in its mentioned position, and operatively connected interlock means-Whose function is determined Toy the position of said carrier and'said valve for insuring the desired sequence of operatioh of the machine.

it. In a machine tool having a work rotatable spindle and a to and fro moving tool carrier, hydraulic means for moving the tool carrier to and fro relative to Work on the spindle, comprising pressure circuits for moving the carrier in one direction, one of said circuits moving the carrier in fixed ratio with the spindle speed, and another circuit moving the carrier in an opposite direction, a cylinder and a piston therein, and fluid connections extending from a hydraulic pressure source connecting first said circuits to the cylinder at one side of the piston and to connect the last circuit to the other side of said piston, such hydraulic circuits including a control valve, electrical means for moving said valve in opposite directions to change the directionof flow through said first hydraulic circuits, said electrical means including switches operated by the movement of said valve for opening and closing an operating circuit forming a part of said elect1 ical means, and means for rendering said electrical means effective when said carrier is in certain of its positions.

15. A machine tool having a work spindle and a to and fro moving tool carrier, hydraulic means for moving the carrier to and fro relative to work on the spindle and comprising a cylinder and a piston therein and fluid connections with the cylinder at both sides of the piston, and such connections including a control valve, electrical means for moving sa -l valve in opposite directions to change the dir -ion of fluid flow through the hydraulic connections, said electrical means including switches operated by the movement of said valve for opening and closing an operable circuit forming a part ofsaid electrical means, and means for rendering said electrical means effective when said .carrier is in certain of its positions, the electrical means comprising means operated by the tool slide at the end of its work performing stroke for causing operation of said control valve to exhaust the work performing feeding pressure from said piston and enabling pressure on the other side of the piston to move the piston in opposite direction for reversing movement of thetool carrier, and hand re-set means for operating said control valve to supply work feeding pressure to said piston.

16. A machine tool having a work spindle and a to and fro moving tool carrier, hydraulic means for moving the carrier to and fro relative to work on the spindle and comprising a cylinder and a piston therein and fluid connections with the cylinder at both sides of the piston, and such connections including a control valve, electrical means for moving said valve in opposite directions to change the direction of fluid flow through the hydraulic connections, said electrical means including switches operated by the movement of said valve for opening and closing an operable circuit forming a part of said electrical means, and means for rendering said electrical means effective when said carrier is in certain of its positions, a device responsive to pressure on the work performing sideof said piston when the tool slide has reached the end of its work performing stroke to close a circuit controlling the movement of said control valve, whereby when said circuit is closed said control valve is operated to exhaust the pressure on the work performing side of the piston, and-a hand re-set means for causing said control valve to be actuated to again establish pressure on the work performing side of said piston. I

17. In a machine tool as set forth in claim 14 further characterized by means operated by the tool carrier in different positions of its movement toward the spindle for actuating said control valve whereby the rate of speed of movement of the tool carrier may be varied.

18. In a machine tool having a work rotatable spindle, a to and fro moving tool carrier, means 7 for rotating the spindle, hydraulic means for moving the tool carrier to and fro relative to a work piece on the spindle, said hydraulic means comprising a pressure line for feeding the carrier toward the work in-fixed ratio with the speed of the spindle and another pressuie line for feeding the tool toward the spindle at faster speed; means for moving the tool carrier away from the spindle subordinate to said hydraulic pressures in said lines, a valve connected with said pressure lines and having ports therein for controlling the supply from said pressure lines to change the speed of movement of the work carrier toward the spindle as well as for relieving the forward feeding pressures to render them ineffective for moving the tool carrier, means for moving said valve to its various positions including means controlled by the position of said tool carrier in its forward movement, whereby either one of said pressure lines may be made effective, and automatic means rendered eifective when the tool slide is at the end of its work performing movement for shifting the valve to relieve said feeding pressures, whereby the tool carrier is moved away from the spindle.

; 19. In a machine tool as set forth in claim 18 further characterized by indexing means for ro- I tating parts of the machine to effect relative movement betweenthe tool carrier and the spindle for shifting relative positions of the same, means for actuating the indexing means, means actuated by the tool carrier when in a predetermined position of its reverse movement away from the spindle for rendering operable said indexing actuating means, means actuated by the movement of the indexing means for.rendering the above stated functions of the machine inoperative during the operation of the indexing means, and a hand re-set device for operating said control valve to supply a pressure for moving the tool carrier toward the spindle after the indexing operation has taken place.

20. In a machine tool having a work rotatable spindle, a to and fro moving tool carrier, means for rotating the spindle, means for moving the tool carrier to and fro relative to a work piece on the spindle including a hydrauliccylinder and piston, a source of low pressure fluid supply constantly connected to the cylinder on the side of the piston which will cause the piston to move.

in a direction to retract the tool carrier from the spindle, a source of high pressure fluid supply, means for connecting the source of high pressure fluid supply with the opposite end of the cylinder on the side of the piston which will cause it to move to advance the tool carrier toward the spindle, a metering device in said high pressure line driven synchronously with the spindle speed whereby the high pressure fluid may be fed to the spindle in metered amounts for performing work, a by-pass in the high pressure line whereby the metering valve may be shunted and high pressure fluid delivered to the cylinder in unmetered amounts for causing rapid movement of the tool slide toward the spindle, and means for controlling said by-pass.

MYRON S. CURTIS. 

